Reason that Mobil 1 darkens is...
- Thread starter JAG
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GC is said to contain esters as well - different ester(s), different properties
Interesting note on some G3 oil's oxidative stability.
How might those thermally activated additives appear after reaching temperature...any relavent changes? Someone reported to me that some constituents may evaporate which accounts as another aspect for additive depletion.
Interesting note on some G3 oil's oxidative stability.
How might those thermally activated additives appear after reaching temperature...any relavent changes? Someone reported to me that some constituents may evaporate which accounts as another aspect for additive depletion.
I see this question brought up all of the time and want to put it to rest. Stated more accurately, the reason that Mobil 1 darkens more so than many other motor oils in an engine is because it darkens more than many others just from being heated to operating temperatures. It is not because it's doing a better job of cleaning like most assume; it does clean well as do many other quality oils but that's not why it gets darker in use than some other oils in same engine use. Put in even simpler terms, it changes color a lot when heated.
And while we're on the topic, Redline oil gets even darker when heated than Mobil 1, given high enough temperatures. Not that it matters; it's just an FYI. Another FYI: Castrol 5W-40, 10W-40, and Gold GC stay very much the same color as they started when heated. I have same info on some other oils but that wasn't the point of this thread, so I'll end here.
Color change is a function of several things: additive package darkening, oxidation of basestocks (bad), and amount of carbon in the oil. For Mobil 1 and Redline, additive package darkening happens easily and well before the basestocks have darkened from oxidation.
How do I know? I heated the oils to many temperatures for many lengths of time. How else would I know?
And while we're on the topic, Redline oil gets even darker when heated than Mobil 1, given high enough temperatures. Not that it matters; it's just an FYI. Another FYI: Castrol 5W-40, 10W-40, and Gold GC stay very much the same color as they started when heated. I have same info on some other oils but that wasn't the point of this thread, so I'll end here.
Color change is a function of several things: additive package darkening, oxidation of basestocks (bad), and amount of carbon in the oil. For Mobil 1 and Redline, additive package darkening happens easily and well before the basestocks have darkened from oxidation.
How do I know? I heated the oils to many temperatures for many lengths of time. How else would I know?
Thanks for the input JAG
Very interesting. Can you say at what temperature they start to darken? If it occurs at a high temp it might indicate the need for a oil cooler on a particular engine.(?)
I'm surprised nobody has asked how a certain oil faired compared to any of the others on the list on page 1. That's what I meant when I said people can look at the list of oils tested and ask questions. I guarantee you all that if we did all poll, the predictions would differ quite a bit from the test results. There are so many misconceptions and false assumptions but once the truth is found from testing, it does make sense. That link that GMborg posted does provide a heck of a lot of insight and goes along way toward squashing misconceptions.
M1 Supersyn is a bit of a mystery oil. We know it has some PAO in the form of Supersyn (extremely viscous PAO) but we don't know what the remainder of the basestocks are which comprise the majority anyway. The older Tri-Synthetic M1 versions were known because M1 was very forthright about it: PAO, ester, and alkylated naphthalene.
M1 Supersyn is a bit of a mystery oil. We know it has some PAO in the form of Supersyn (extremely viscous PAO) but we don't know what the remainder of the basestocks are which comprise the majority anyway. The older Tri-Synthetic M1 versions were known because M1 was very forthright about it: PAO, ester, and alkylated naphthalene.
This thread's main topic and finding isn't up for debate. I hate to break it to you that way but the sooner you know it, the better off you are.
I think most everything turns dark if it's heated to a high enough temp.
It was posted to inform, not debate. It is settled. Debating this is like debating if man can ever make it to the moon.
I'd be more interested in how these oils perform in the presence of metal catalysts like modern bearing materials, iron, aluminum, and all the rest of the metals found in an engine and which the oil is in contact with in a real engine.
When I tested oxidation stability of engine oils in a laboratory for an oil company, we had an apparatus that measured oxygen absorption of hot oil which contained measured amounts of freshly-cleaned copper and iron wire.
This was many years ago, so the results are not really relevant to the oils sold today, but the concept of the standardized test with catalysts available in engines is still valid.
BTW, when I tested it against dyno oils, M1 was so much more stable it was ridiculous. While dyno oils like Amoco, Penzoil, etc went to **** (antioxidants gave up the ghost) in 30 min or so under our test conditions, M1 would go all day.
When I tested oxidation stability of engine oils in a laboratory for an oil company, we had an apparatus that measured oxygen absorption of hot oil which contained measured amounts of freshly-cleaned copper and iron wire.
This was many years ago, so the results are not really relevant to the oils sold today, but the concept of the standardized test with catalysts available in engines is still valid.
BTW, when I tested it against dyno oils, M1 was so much more stable it was ridiculous. While dyno oils like Amoco, Penzoil, etc went to **** (antioxidants gave up the ghost) in 30 min or so under our test conditions, M1 would go all day.
Alan, If you can go 10K miles without your oil turning black, then I am very impressed .. or confused. I would expect most any oil to be very, very, very dark by 10K miles. Maybe you have found a way to prevent soot.
Jag, your data is what it is. You saw certain oils begin to coke, burn, oxidize, blacken, whatever at different rates. I don't think that you can know why the differences were there from just your experiment. I also expect that you don't know the repeatability of your assay, affects of batch variation, actual temperature, ect. I'm not knocking what you did. I think that your observations are interesting. I also don't think that you are suggesting much more than your data supports.
There's my 2 cents worth and it probably didn't help a bit.
Jag, your data is what it is. You saw certain oils begin to coke, burn, oxidize, blacken, whatever at different rates. I don't think that you can know why the differences were there from just your experiment. I also expect that you don't know the repeatability of your assay, affects of batch variation, actual temperature, ect. I'm not knocking what you did. I think that your observations are interesting. I also don't think that you are suggesting much more than your data supports.
There's my 2 cents worth and it probably didn't help a bit.
Gmorg,
The Corolla was the one that went 10k without much discoloring.
The one that surprised me the most was the M1 run for 8k in my VW VR6 which runs very hot.It looked very pretty clean on the dipstick and when drained.
I felt bad changing it.
The Corolla was the one that went 10k without much discoloring.
The one that surprised me the most was the M1 run for 8k in my VW VR6 which runs very hot.It looked very pretty clean on the dipstick and when drained.
I felt bad changing it.
I didn't tell what all of my experiments and data collection details consisted of so it's impossible for anyone to say anything about the validity or lack of validity of my conclusions. Yes this forces you all to rely on faith in my abilities and knowledge that I'm giving correct information. If you don't believe it, go test yourself. As I said, I don't have time to type up all the information and that was never my intention. My notes are extremely volumnous and the testing was highly varied so I can't summarize testing procedures and data collection methods succinctly. I'm sorry this is so disappointing to people. Apparently it is better to provide no information to this forum than any information at all. What I was willing to summarize is general results of one oil vs another; I don't feel that it is worth it anymore. I am a DoD scientist who is a test program manager who also conducts the tests and analyzes data and writes the reports and has been doing so for 7 years, so hopefully that will quell some people's fears that I'm some backwoods redneck heating up oils in a skillet.
This is my last post in this thread. I'm out-a-here!
This is my last post in this thread. I'm out-a-here!
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Naw, a redneck would use his Fry Daddy instead of a skillet.
But you have to agree that providing incomplete information (ie. no details on how the tests were performed) may just cause a lot of confusion, like it did here.
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